This invention generally relates to the launching into space of multiple payloads, and specifically to the provision of continuing support services for such payloads.
Large spacecraft, including the Shuttle and large expendable satellites, are typically comprised of one or a few large and many more small individual payloads. For example, the Voyager spacecraft, best known for the dramatic photographs taken of the outer planets, carries magnetometers, radiation detectors, and other small experiments which continue to send back data long after the primary photographic missions have ended. As another example, large communications satellites often contain several different transponders (radio receiver/transmitter pairs). All of these spacecraft to date have been single purpose, customized designs. None offered significant modularity or adaptability.
A proposed Industrial Space Facility contained provisions for several attached payloads within a pressurized volume. The Space Shuttle fleet includes provisions for attached payloads, including the pressurized mid-deck lockers, unpressurized Get Away Special canisters (known as GAS cans), and the Hitchhiker program attachment points which provide limited bus services to attached payloads. Several devices, including the Spacelab and Spacehab have been designed to extend the Shuttle pressurized or unpressurized payload bay capabilities. All of these programs, however, suffer from shortcomings which the Modular Mother Satellite Bus (MMSB) for attached payloads of this invention will rectify.
The above mentioned Industrial Space Facility, which was never made operational, was a very large and expensive design which would have required the entire lift capability of a Shuttle for launch, as well as periodic tending by Shuttle based astronauts. It was intended to be pressurized so that astronauts could work inside, but as designed, had limited capability for supplying bus services to attached unpressurized payloads.
The Shuttle GAS cans are unique to the Shuttle. These are passive devices, and are not provided any substantial bus services. They do not exercise pointing control authority over the Shuttle, and suffer the restrictions of operating exclusively in the Shuttle payload bay, including the expense of man-rating all equipment, re-radiation of infra-red light from the Shuttle structure, environmental contamination due to water and propulsion byproducts emitted by the Shuttle, and radio frequency energy in the vicinity of the Shuttle making certain experiments difficult or impossible to perform.
The Shuttle Hitchhiker program provides limited bus services to attached payloads but only operates within the Shuttle payload bay. The relatively short duration of the Shuttle flights is a severe limitation for certain experiments requiring long orbital flights. Hitchhiker payload pointing is also not provided as a Shuttle bus service.
The Spacelab platform operates only as a Shuttle attached payload. It includes provision for certain attached payloads as well as internal pressurized volume, but must be specially configured and extensively reworked for each payload.
The Spacehab module will also operate exclusively as a Shuttle attached payload and provides additional pressurized volume, extending the Shuttle mid-deck volume. It does not provide any additional bus services, but distributes standard services provided by the Shuttle to the internal payloads.
The EURECA platform was built in Europe and is designed to accommodate several payloads. Nevertheless, the craft was intended to carry a specific array of attached payloads and for a unique mission, supported by all of the payloads. It did not contain any provisions for incorporation of as yet undesigned payloads, standard interface features, or significant modularity.
This invention is designed specifically to ease these limitations by providing an unmanned expandable or recoverable craft enabling multiple attached subsidiary payloads with unrelated functions to be launched as either primary or secondary payloads on conventional expendable rockets (or on one of the Space Shuttles), and to share space launch and orbital flight services, thereby reducing cost, improving the payload environment, and increasing the bus services available to attached payloads exposed to the space environment.